Substrate receiving method

ABSTRACT

A substrate receiving apparatus and a method thereof that prevents substrate damage from occurring when a substrate is loaded/unloaded on/from a cassette. The present invention includes a cassette having a plurality of plates inside so as to receive a plurality of substrates; a cassette loading unit uploading/downloading the cassette; a port supporting the cassette loading unit; and a plurality of auxiliary plates inserted inside the cassette from outside. The method includes downloading a cassette so as to move substrates from plates of the cassette to auxiliary plates, unloading and loading the substrates placed on the auxiliary plates from/on the cassette, and uploading the cassette so as to move the substrates from the auxiliary plates to the plates of the cassette.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 10/286,763 filed Nov. 4, 2002, now U.S. Pat. No. 6,824,618;which claims the benefit of Korean Patent Application No. P2001-81212,filed Dec. 19, 2001, which is hereby incorporated by reference for allpurposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate receiving apparatus andmethod thereof that prevents substrate damage from occurring when asubstrate is loaded/unloaded on/from a cassette.

2. Discussion of the Related Art

Generally, liquid crystal displays (LCDs) having characteristics ofpower-saving driving, full color realization, high image quality, andthe like are widely used as screens in various devices such as watches,calculators, notebook computers and personal computers.

A process of fabricating such a liquid crystal display device mainlyincludes a substrate preparing process for constituting a liquid crystaldisplay panel and a module assembly process.

In the related art, while the above-mentioned processes are carried out,a specially constituted substrate receiving apparatus is used fortransferring a plurality of substrates and panels.

A substrate receiving apparatus for a liquid crystal display deviceaccording to a related art is explained by referring to the attacheddrawings as follows.

FIG. 1A illustrates a layout of a substrate receiving apparatus and aconveying robot according to a related art.

FIG. 1B illustrates a cross-sectional view of a substrate receivingapparatus according to a related art.

FIG. 1C illustrates a layout of a cassette-fixing clamp unit accordingto a related art.

Referring to FIG. 1A and FIG. 1B, a substrate receiving apparatusaccording to a related art includes a cassette 102 that receives aplurality of substrates 104, a stage 103 supporting the cassette 102,and at least one port 100 under the stage 103. In this case, thecassette 102 is able to receive about 20 substrates.

A conveying robot 101 selects one of various ports 100, approaches thecassette 102 on the selected port 100, and then loads/unloads thesubstrates 104 one by one for processing the substrate 104.

Referring to FIG. 1C, a fixing clamp 105 is used for fixing the cassette102 mounted on the stage 103 (shown in FIG. 1B). A cylinder 106 isinstalled on the clamp 105 so as to move the clamp forward/backward in adirection of the arrow. A side roller 107 is installed on the clamp 105so as to reduce friction with the cassette 102.

Once the cassette is fixed thereto by the clamp 105, the conveying robot101 carries out the function of taking the substrates 104 out one by oneto process the substrates 104.

FIG. 2A and FIG. 2B illustrate receiving statuses of the substrates 104put in the cassette 102 according to a related art.

Referring to FIG. 2A, plates 202 are placed at both inner sides of acassette 102 so as to support a substrate 104. The substrate 104 isplaced on the plates 202. In this case, the plates 202 leave apredetermined interval from each other so that a robot arm 201 may entera space between the substrates 104. Yet, a central portion of each ofthe substrates 104 droops downward due to its own weight.

Referring to FIG. 2B, an extent of the drooping increases as thesubstrate 104 is made to be thinner. Once the substrate 104 droopsdownward, the robot arm 201 advancing into the cassette forloading/unloading the substrate 104 fails to avoid touching anothersubstrate. Hence, there is a chance the substrates may be damaged or forfailure of the substrate.

In order to overcome such a problem there is a method for increasing aninterval 206 between the upper and lower plates 202 or a length 207 ofeach of the plates 202. However, it is very expensive to modify all thecassettes used in a product line. Besides, it is troublesome to use adifferent cassette according to a thickness of the correspondingsubstrate 104.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a substrate receivingapparatus and method thereof that substantially obviates one or moreproblems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide a substratereceiving apparatus and method thereof that prevents substrate damagegenerated from the process of loading/unloading substrates on/from acassette.

Another advantage of the present invention is to provide a substratereceiving apparatus and method thereof that provides a general cassettereceive substrates therein regardless of various kinds of thickness ofthe substrates.

Additional features and advantages of the invention will be set forth inpart in the description which follows and in part will be apparent fromthe description, or may be learned from practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a substratereceiving apparatus according to the present invention includes acassette having a plurality of plates inside so as to receive aplurality of substrates; a cassette loading unit uploading anddownloading the cassette; a port supporting the cassette loading unit;and a plurality of auxiliary plates inserted inside the cassette fromoutside.

The plates may be arranged at both inner sides of the cassette so as toleave a predetermined interval from each other.

The auxiliary plates have a length that is substantially longer than theplates.

The auxiliary plates are placed substantially parallel with the plates,and a vertical interval between the auxiliary plates is about equal tothat of the plates.

The substrate receiving apparatus further includes a plurality ofauxiliary plate support bars arranged on the port.

Each of the auxiliary plate support bars is capable of revolving.

The substrate receiving apparatus further includes a plurality of clampsfixing the cassette to the cassette loading unit.

The substrate receiving apparatus further includes a plurality ofcylinders moving the clamps forward and backward, respectively, and aplurality of side rollers that substantially reduce friction between theclamps and cassette.

In another aspect of the present invention, a substrate receiving methodincludes downloading a cassette so as to move substrates from plates ofthe cassette to auxiliary plates; unloading and loading the substrateson the auxiliary plates from/on the cassette; and uploading the cassetteso as to move the substrates from the auxiliary plates to the plates ofthe cassette.

The method further includes fixing the cassette to a cassette loadingunit having uploading and downloading functions.

The method further includes inserting the auxiliary plates inside thecassette from outside before the cassette is downloaded.

The auxiliary plates are inserted inside the cassette by revolvingauxiliary plate support bars.

The auxiliary plates are inserted between the plates so as to besubstantially parallel with the plates.

Namely, the present invention loads/unloads a substrate having beenplaced on the auxiliary plates to be substantially longer than theplates installed inside the cassette, thereby preventing substratedamage.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1A illustrates a layout of a substrate receiving apparatus and aconveying robot according to a related art;

FIG. 1B illustrates a cross-sectional view of a substrate receivingapparatus according to a related art;

FIG. 1C illustrates a layout of a cassette-fixing clamp unit accordingto a related art;

FIG. 2A and FIG. 2B illustrate receiving statuses of a substrate put ina cassette according to a related art;

FIG. 3A illustrates a block diagram of a glass substrate etchingapparatus according to the present invention;

FIG. 3B illustrates a glass substrate etching apparatus according to thepresent invention;

FIG. 4A illustrates a layout of a substrate receiving apparatus and aconveying robot according to the present invention;

FIG. 4B illustrates a cross-sectional view of a substrate receivingapparatus according to the present invention;

FIG. 4C illustrates a layout of a substrate receiving apparatusaccording to the present invention;

FIG. 5A illustrates a cross-sectional view of a substrate receivingapparatus according to the present invention for explaining a status ofreceived substrates;

FIG. 5B illustrates a cross-sectional view of auxiliary plates and anauxiliary plate support bar of a substrate receiving apparatus accordingto the present invention;

FIG. 5C illustrates a layout of auxiliary plates and an auxiliary platesupport bar of a substrate receiving apparatus according to the presentinvention;

FIGS. 6A to 6C illustrate cross-sectional views of a method of receivinga substrate according to the present invention; and

FIG. 7A and FIG. 7B illustrate diagrams for explaining the operation ofan auxiliary plate of a substrate receiving apparatus according to thepresent invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, example of which is illustrated in the accompanying drawings.Wherever possible, the same reference numbers will be used throughoutthe drawings to refer to the same or like parts.

FIG. 3A illustrates a block diagram of a glass substrate etchingapparatus according to the present invention.

FIG. 3B illustrates a glass substrate etching apparatus according to thepresent invention.

Referring to FIG. 3A, a glass substrate etching apparatus according tothe present invention includes an etching unit 301, an etchant recyclingunit 302 removing impurities from an etchant used by the etching unit301 for etching a substrate so as to store the impurity-removed etchant.A deionized (DI) supply unit 303 provides deionized water. An undilutedetchant supply unit 304 supplies an undiluted etchant. An etchant mixingunit 305 mixes the DI water supplied from the DI supply unit 303, theundiluted etchant supplied from the undiluted etchant supply unit 304,and the impurity-removed etchant supplied from the etchant recyclingunit 302 with each other. An etchant heating unit 308 heats the mixedetchant having been mixed by the etchant mixing unit 305.

Moreover, the glass substrate etching apparatus further includes acleaning unit 306 removing the etchant remaining on the etched substrateusing DI water and a drying unit 307 drying the cleaned substrate.

In this case, the etchant may include a HF solution.

The etching unit 301 includes an airtight container 301 a and a supplypipe 301 b connected to the container 301 a through a pipe so as tosupply nitrogen or oxygen.

Moreover, the etching unit 301 further includes a temperature measuringdevice 301 c so as to measure a temperature difference generated fromexothermic reaction between the substrate to be etched in the container301 a and the etchant. Namely, the etching reaction generates heat fromthe reaction between HF and silicon oxide contained in the substrate.The heat generated from the exothermic reaction is measured, whereby theextent of the etching can be known regardless of the concentration ofthe etchant or etching time. Hence, a thickness of a substrate and thetemperature of the reaction heat according to a number of substrates arecalculated, whereby the etching is stopped once the calculatedtemperature reaches a certain temperature. Therefore, the presentinvention provides an etched substrate having the uniform thickness.

The etchant recycling unit 302 includes a filter 302 a removingimpurities from the etchant used to etch the substrate and a storagetank 302 b storing the impurity-removed etchant having been purified bythe filter 302 a. In this case, the filter 302 a can be located at arear end of the storage tank 302 b so as to remove precipitates sunk inthe storage tank 302 b. At least one of the filters 302 a can be formedat one or both of the front and rear ends of the storage tank 302 b.

A concentration measuring device 305 a is installed at one side of theetchant mixing unit 305 so as to measure a concentration inside theetchant mixing unit 305, and a pipe cooling water (PCW) coolant pipe(not shown in the drawing) may be formed at the other side of theetchant mixing unit 305 so as to uniformly maintain a temperature of theetchant.

The concentration of the etchant such as HF or the like is uniformlymaintained uniformly using the concentration measuring device 305 a.This is because an etching time depends on the concentration of theetchant as well as a bubble pressure by nitrogen or oxygen bubbles. Forinstance, the etching time is lengthened if the concentration of theetchant is low. Stains are formed on a surface of the glass substratedue to irregular etching by abrupt exothermic and chemical reaction ifthe concentration is high.

Moreover, the etching unit 301, etchant heating unit 308, etchant mixingunit 305, and etchant recycling unit 302 are connected to each otherthrough pipes so as to allow the etchant flow therein. Besides, at leastone pump can be formed between the pipes so as to allow the etchant tomove therein.

A substrate receiving apparatus for receiving the thin substrates in aliquid crystal display and a method thereof according to the presentinvention are explained in detail by referring to the attached drawingsas follows.

FIG. 4A illustrates a layout of a substrate receiving apparatus and aconveying robot according to the present invention.

FIG. 4B illustrates a cross-sectional view of a substrate receivingapparatus according to the present invention.

FIG. 4C illustrates a layout of a substrate containing apparatusaccording to the present invention.

Referring to FIG. 4A and FIG. 4B, a substrate containing apparatusaccording to the present invention includes a cassette 402 having plates412 to support a plurality of substrates inside the apparatus. Acassette loading unit 403 uploading/downloading the cassette 402, a port400 supporting the cassette loading unit 403, and auxiliary platesupport bars 410 placed at both sides of the cassette so as to supportauxiliary plates 409 inserted inside the cassette 402 from outside.

Referring to FIG. 4C, the substrate containing apparatus according tothe present invention further includes clamps 405 fixing the cassette402 on the cassette loading unit 403, cylinders 406 moving the clamps405 forward/backward, and side rollers 407 for substantially reducingfriction between the clamps 405 and the cassette 402.

In this case, the plates 412 are arranged at both inner sides of thecassette 402 so as to leave a uniform predetermined interval from eachother and the auxiliary plates 409 are attached to lateral sides of theauxiliary plate support bars 410 so as to provide approximately the samevertical interval between the plates 412 from each other.

Hence, the auxiliary plates 409 are supported by the auxiliary platesupport bars 410 arranged on the port 400, and can be inserted in thecassette 402 from outside by the revolving auxiliary plate support bars410.

The conveying robot arm 401 approaches the above-constituted substratereceiving apparatus according to the present invention so as tounload/load the substrates from/on the cassette 402 one by one for theprocessing of the substrates.

FIG. 5A illustrates a cross-sectional view of a substrate receivingapparatus according to the present invention for explaining a status ofreceived substrates in the cassette.

FIG. 5B illustrates a partial cross-sectional view of auxiliary platesand an auxiliary plate support bar of a substrate receiving apparatusaccording to the present invention.

FIG. 5C illustrates a layout of auxiliary plates and an auxiliary platesupport bar of a substrate receiving apparatus according to the presentinvention.

Referring to FIG. 5A, when a conveying robot arm 401 enters a cassette402 for loading/unloading substrates 404, there is less chance for thesubstrates 404 to be damaged by the robot arm 401 since the substratesare placed on auxiliary plates 409. This is because each of thesubstrates 404 droops to a substantially lesser extent when thesubstrates 404 are placed on the auxiliary plates 409 substantiallylonger than the plates 412.

The present invention includes the above-explained auxiliary plates 409,thereby enabling a thin substrate to be loaded/unloaded a thin substratewithout causing substantially any damage on the thin substrate. Thethickness of the substrate may be about 0.7 T (mm), 0.63 T (mm), or 0.5T (mm).

Referring to FIG. 5B and FIG. 5C, the auxiliary plates 409 are attachedto sides of the auxiliary plate support bars 410 so as to leave thesubstantially the same vertical interval A approximately equal to thevertical interval of the plates 412 from each other, and are insertedinside the cassette 402 by about 90° revolutions of the auxiliary platesupport bars 410. Hence, the substrates can be received using theprevious cassette 402 without any considerable alteration of thecassette 402 in accordance with a corresponding thickness of thesubstrate 404.

A method of receiving a substrate using a substrate receiving apparatusaccording to the present invention is explained as follows.

FIGS. 6A to 6C illustrate cross-sectional views of a method of receivinga substrate according to the present invention.

FIG. 7A and FIG. 7B illustrate diagrams for explaining the operation ofan auxiliary plate of a substrate receiving apparatus according to thepresent invention.

Referring to FIG. 6A, a cassette 402 receiving substrates 404 inside ismounted on a cassette loading unit 403 having uploading/downloadingfunctions, and then fixed thereto using clamps 405. The clamps 405 arearranged at corners of the cassette 402. In this case, the substrates404 are placed on plates inside the cassette 402.

Referring to FIG. 6B, auxiliary plate support bars 410 at both sides ofthe cassette 402 are revolved by about 90° so that auxiliary plates 409are inserted inside the cassette 402. In this case, the auxiliary plates409 are placed in parallel with each other between the plates 412 insidethe cassette 402.

Referring to FIG. 6C, the cassette 402 is downloaded using the cassetteloading unit 403. In this case, as the cassette 402 goes down, thesubstrates having been put on the plates 412 are placed on the auxiliaryplates 409. Since the auxiliary plates 409 are substantially longer thanthe plates 412, the extent of drooping of each of the substrates 404 isreduced.

A conveying robot arm 401 enters the cassette 402 so as to unload thesubstrates 404 on the auxiliary plates 409 from the cassette 402 toprocess of the substrates 404. Once the process of the substrates iscompleted, the robot arm 401 loads the substrates inside the cassette402 again. In this case, the substrates are placed on the auxiliaryplates 409.

Subsequently, the cassette loading unit 403 is driven so as to uploadthe cassette 402. In this case, as the plates 412 go upward, thesubstrates 404 having been placed on the auxiliary plates 409 are placedon the plates 412.

Thereafter, the cassette 402 is transferred to another port for the nextprocess.

Meanwhile, FIG. 7A and FIG. 7B illustrate the case where the auxiliaryplates 409 are inserted inside the cassette 402 by the revolvingauxiliary plate support bars 410. The auxiliary plates 409, which areinserted to be near to the plates 412, as shown in FIG. 7A, collide withthe substrates 404. Hence, the auxiliary plates 409, as shown in FIG.7A, should be inserted in proper positions between the plates 412 toavoid collision.

Accordingly, the substrate receiving apparatus in a liquid crystaldisplay device and method thereof according to the present inventionhave the following advantages or effects.

First, the present invention uses auxiliary plates longer than theplates supporting the substrates inside the cassette, thereby preventingsubstrate damage from occurring when the substrates are loaded/unloadedon/from the cassette.

Second, the present invention uses the related art cassette withoutreplacing or altering the cassette in accordance with the correspondingthickness of the substrate, thereby minimizing the process cost andtime.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method for receiving a substrate comprising: transferring acassette, receiving the substrate on the plates of the cassette, to acassette loading unit having uploading and downloading functions; fixingthe cassette on the cassette loading unit using clamps, the clampsarranged at corners of the cassette; inserting the auxiliary platesbetween plates of the cassette from outside by revolving at least twoauxiliary plate support bars, wherein the auxiliary plates are supportedby the auxiliary plate support bars arranged on a port, supporting thecassette loading unit, at both sides of the cassette, wherein theauxiliary plates are inserted to be substantially parallel with theplates of the cassette and to be respectively lower than the plates ofthe cassette, and wherein the auxiliary plates are longer than theplates of the cassette; after inserting the auxiliary plates, downwardlymoving the cassette by the cassette loading unit so as to movesubstrates from the plates of the cassette to auxiliary plates longerthan the plates of the cassette, the downwardly moving the cassetteoccurring while simultaneous moving the same substrates from plates ofthe cassette to auxiliary plates; unloading and loading the samesubstrates from/on the auxiliary plates in the cassette; upwardly movingthe cassette by the cassette loading unit so as to move the samesubstrates from the auxiliary plates to the plates of the cassette, theupwardly moving the cassette occurring while simultaneous moving thesame substrates from the auxiliary plates to the plates of the cassette;and wherein the auxiliary plates support the same substrates only withinthe cassette, and wherein the same substrates in the cassette areunloaded from the auxiliary plate on a conveying robot arm, entered inthe cassette for unloading the same substrates, and are loaded from theconveying robot arm on the auxiliary plate, again entered in thecassette for loading the same substrates.
 2. The method for receiving asubstrate of claim 1, further comprising: storing an etchant in anetching unit; removing impurities from the etchant in an etchantrecycling unit; storing deionized water in a deionized supply unit;storing undiluted etchant in an undiluted etchant supply unit; mixingthe deionized water, the undiluted etchant, and the impurity-removedetchant in an etchant mixing unit; heating the mixed etchant in anetchant heating unit; and removing the etchant remaining on thesubstrate in a cleaning unit; wherein the etching unit, the etchantheating unit, the etchant mixing unit, and the etchant recycling unitare connected to each other through pipes; and wherein the deionizedsupply unit and the undiluted etchant supply unit are both connected tothe etchant mixing unit through pipes.
 3. The method of claim 2, whereinthe etchant includes an HF solution.
 4. The method of claim 2, whereinthe etching unit includes an airtight container, a gas supply pipe, anda temperature measuring device.
 5. The method of claim 2, wherein theetchant recycling unit includes a filter removing impurities from theetchant and a storage tank storing the impurity-removed etchant.
 6. Themethod of claim 2, wherein the etchant mixing unit includes aconcentration measuring device and a PCW coolant pipe.